| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ultra-rapid-hardening cement composition having a high flowability-retaining effect and an excellent rapid hardening property by compounding a ultra-rapid hardening cement and a cement-dispersing agent comprising a polycarboxylic acid-based high molecular compound or comprising a polycarboxylic acid-based high molecular compound and one or more kinds of components selected from a polyalkylene glycol and a 8-22C fatty acid. SOLUTION: This ultra-rapid-hardening cement composition comprises 100 pts.wt. of a ultra-rapid-hardening cement containing calcium aluminate as a main component and 0.01-5 pts.wt. of a cement dispersing agent. The cement- dispersing agent is selected from a powdery material obtained by drying and pulverizing a mixture containing water and a polycarboxylic acid-based high molecular compound having constituting units of formula I and II and a powdery material containing particles containing a polycarboxylic acid-based polymer having a polyalkylene glycol chain and one or more kinds of compounds selected from a polyalkylene glycol and a 8-22C fatty acid. In the formula I and II, R1-R3 are each hydrogen or methyl; R4 is a 1-3C alkyl; M is hydrogen, an alkyl metal or the like; Y is CH2O, COO or the like; (n) is 20-109. |
